Exchange to value without use third variable

7./*Write a program to Exchange  to value without use third variable*/

#include<stdio.h>

#include<conio.h>

main()

{

int a,b;

clrscr();

printf("\n ENTER VALUE A:-");

scanf("%d",&a);

printf("\n ENTER VALUE B:-");

scanf("%d",&b);

a=a+b;

b=a-b;

a=a-b;

printf("\n a=%d,b=%d",a,b);

getch();

}

OUTPUT

            ENTER VALUE A:10

            ENTER VALUE B:15

            A=15,B=10